Hydrogen Peroxide Tuned Morphology and Crystal Structure of Barium Vanadate-Based Nanostructures for Aqueous Zinc-Ion Storage Properties.

Improving the layered-structure stability and suppressing vanadium (V) dissolution during repeated Zn 2+ insertion/extraction processes are key to promoting the electrochemical stability of V-based cathodes for aqueous zinc (Zn)-ion batteries (AZIBs). In this study, barium vanadate (Ba 2 V 2 O 7 , BVO) nanostructures (NSs) are synthesized using a facile hydrothermal method. The formation process of the BVO NSs is controlled by adjusting the concentration of hydrogen peroxide (H 2 O 2 ), and these NSs are employed as potential cathode materials for AZIBs. As the H 2 O 2 content increases, the corresponding electrochemical properties demonstrate a discernible parabolic trend, with an initial increase, followed by a subsequent decrease. Benefiting from the effect of H 2 O 2 concentration, the optimized BVO electrode with 20 mL H 2 O 2 delivers a specific capacity of 180.15 mA h g -1 at 1 A g -1 with good rate capability and a long-term cyclability of 158.34 mA h g -1 at 3 A g -1 over 2000 cycles. Thus, this study provides a method for designing cathode materials with robust structures to boost the electrochemical performance of AZIBs.